Character help

Hi all! I'm a pretty seasoned player I'd like to think, and with our latest campaign (Eternal Night of Lockwood) my GM allowed us to do some fun things. I went in knowing I was making 3 characters (one main character, 2 other characters to play if they were slain/while they rest/what have you).

Anyways, one of my secondary characters, we decided, was going to be a vampire thrall. However in looking through the main book and main gauche... I'm struggling to find information on it. I know it *has* to be there, otherwise my GM wouldn't let me do this, but they're currently sleeping and I'm trying to write some lore. Any info you have where I can find this in the books or other supplementary material, or if you yourself happen to know, please help.